Various projects are being carried out to clarify intraocular fluid movement in rhesus monkeys. A method has been perfected for spectrophotometric determinations of ascorbic acid concentration in ocular and systemic fluids. Clinical, physiologic, and morphologic studies of the ocular alterations following an insult from intracarotid hyperosmotic mannitol show transient alteration of clinical and physiological status, despite permanent disruption of the pigmented epithelial layer of the pars plana and pars plicata of the ciliary body.